code: def test_pham_weight_positive(get_covmats):
      """Test pham's ajd weights: must be strictly positive"""
      n_matrices, n_channels, w_val = 5, 3, 2
      covmats = get_covmats(n_matrices, n_channels)
      w = w_val * np.ones(n_matrices)
      with pytest.raises(ValueError):  # not strictly positive weight
          w[0] = 0
          ajd_pham(covmats, sample_weight=w)
  
file_path: pyRiemann/tests/test_utils_ajd.py
imports: from numpy.testing import assert_array_equal
  import numpy
  import pytest
  from pytest import approx
  from pyriemann.utils.ajd import rjd, ajd_pham, uwedge
label_desc: Use image node_id 4 for calling a global function with example usage: test_pham_weight_positive(get_covmats) without return types